Untitled

Lyttelton Times, Volume CXVIII, Issue 18583, 9 December 1920, Page 10

The floating crane recently supplied fiom Great Britain to an Australian dookyard is one of th© giant cranes of th® world. It is capable of lifting a load of 150 tons and swinging it within a radius of 90 feet. In non-British cranes of this kind the entire weight of the load and the swinging arm is poised on the top of the steel tower which rises from the centre of the ponton, but in this British design tho whole of the dead weight is carried on a. large “ roller path ” fixed to the deck of the pontoon Dangerous stresses are thus avoided; material is saved; and tho life of the crane prolonged. The crane haa been officially tested lip to 200 tons with complete success, all the performances calculated for by the builders having been realised. No moving ballast is used in the pontoon, and at no time is the angle of tilt more than about four degrees. Two cranes of a similar type have been at work in the same for six years. A noteworthy feature of the crane (says the “Times of Natal”) is that, although designed for heavy loads, it handles light loads with case and rapidity. All the machinery on board is electrically driven, power being obtained ■ from a steam dynamo or from shore by means of a flexible cable.

The a maniac facility with which bats aypid while flying in tho dark has been' explained in a number of ways. Very keen eight, an .acute sense of touch especially at the wing tips, or a sense of which we have no knowledge, have all been suggested to account for tlua peculiarity. Experiments have been made by Dr Hamilton Hartridge, of King’s College, Cambridge, states the “ Lancet.”, to prove that neither sight nor touch guides bats in their flight in the dark. On summer evenings pipistrelle hats (a species of small bats common in Great Britain), 100 to 200 at a time,- flew through open windows into rooms communicating by a door. When electric light was turned on they all flew in the same direction, but even when the light was turned off thero did not seem to be any collisions. Threads were placed in their paths, and yet, in ebsolut© darkness, the bats neither collided nor touched the threads. In the darkness they could tell whether the. door was shut, wide open, or just sufficiently open for thorn to paes. The bats are believed to be directed by a special sense of hearing and by sound waves.